Device for producing off-center necked ends on spun tubing



R. H. GREENE FAL Filed Oct. 30. 1956 DEVICE FOR PRODUCING OFF-CENTER NECKED ENDS ON SPUN TUBING April 19, 1960 BY WILLIAM A. KOONS 7% #MVM ATTO RNEYS United States Patent C) DEVICE FOR PRODUCING OFF-CENTER NECKED ENDS ON SPUN TUBING Raymond H. Greene, Detroit, and William A. Koons,

' Allen Park, Mich., assignors to Calumet & Hecla, Inc., V

i 'Ihis invention relates to a method of and apparatus for producing tubing having an off-center necked end.

One object of this invention is to provide a method for producing tubing having an off-center necked end and more particularly to provide a method in which the olf-center necked end produced is substantially parallel with the tube axis and is formed from a length of tubing initially having a concentric or on-center necked end. A -Another object of the invention is to provide apparatus for carrying out the method.

Still another object of the invention is to provide apparatus for producing an'oif-center necked end on a length of tubing initially having a main body portion and a necked end portion contiguous with the main body portion and generally concentric therewith. Afurther object of the invention is to provide apparatus as described in the previous paragraph in which the olf-center necked end produced is disposed substantially parallel to the tube axis and has a wall thereof in 'substantially straight line continuation of the wall of the main body portion of the tube.

' A still further object of the invention is to provide apparatus as described above including means for controlling the opening size and end shape of the off-center neck during the operation of the apparatus.

` Other objects and features of the invention will become apparent as the description proceeds, especially when taken in conjunction with the accompanying drawing, illustrating a preferred embodiment of the invention wherein:

Fig. l is a front elevational view of a press embodying the invention and suitable for carrying out the method, shown partly in section and with the press open.

Fig. 2 is a view similar to Fig. 1 but shows the press closed.

Fig. 3 is a sectional view taken along the line 3--3 on Fig. 1.

"`-Fig. 4 is a sectional view taken along the line 4-4 on Fig". 2.`

'if Fig. 5 is an elevational view of a tube having a concentric necked end from which may be produced a tube having an olf-center necked end by the apparatus shown in'Figs. 1 to 4.

lFig'. 6 is an elevational view of a tube having an offcenter necked end as produced according to the method and by the apparatus of Figs. 1 to 4.

fFig. 7 is an end view of the tube shown in Fig. 6. Prior to the employment of the apparatus shown in Figs. l to 4 to produce an olf-center necked end on a length of tubing, the length of tubing is rst formed to provide a concentric necked portion at one end. Fig. 5 illustrates a tube 10 having a main body portion 12 of uniform circular cross-section and a necked end 14 vconcentric with the main body portion, the necked end 14 comprising a cylindrical end portion 16 and a tapered portion 18 connecting into the main body portion. The necked end 14 may be formed on the end of the tube 10 n 2,933,123 Patented Apir. 19, 196i) ICC.

in any suitable manner and for example this may be accomplished by a spinning operation such as described at length in U.S. Reissue Patent No. 22,465. Briefly the spinning operation therein described involves providing a tool having a tapered female die opening for receiving one end of the tube 10, and thereafter relatively rotating the tool and the tube and at the same time relatively moving the tool and tube toward each other. The end of the tube is thus reduced to provide the concentric necked portion 14.

The tube 10 is then placed in the press 20 to laterally off-set the necked portion 14 to form the tube 22 shown in Fig. 6 having the main body portion 24 corresponding to the main body portion 12, and the oft-center necked end portion 26. The off-center necked end portion 26 has a cylindrical end portion 28, one side wall 30 of which is in substantially straight line continuation of the corresponding side wall of the cylindrical main body por tion 22, and the opposite side wall of the cylindrical necked portion 28 connecting into the corresponding side Wall of the main body portion by the tapered arcuate portion 32. The axis of the cylindrical portion 28 is parallel to the axis of the main body portion 22.

The press 20 compirses a base 34 having a pair of laterally spaced posts 36 at the rear which are rigidly secured to the base and extend upwardly therefrom in parallel relation. The lower ends of the posts 36 are set into openings 38 in the base and locked in position by any suitable means such as the set screws 40. A head 42 is disposed above the base and is formed with a pair of vertically extending through passages 44 respectively slidably receiving the upper ends of the posts 36 to permit vertical sliding movement of the head relative to the base. A vertically extending rod 46 is secured to the top of the head and is connected Vto a suitable power device (not shown) such as a double acting hydraulic cylinder for raising and lowering the head relative to the base.

The press includes a pair of clamps 48 and 50, the clamp 48 being secured to the under side of the head by a pair of bolts 52 and the clamp 50 being secured to the top side of the base directly beneath the clamp 48 by a pair of bolts 54. A spacer plate 55 is interposed between clamp 48 and the head to properly locate the clamp 48 vertically with respect to clamp 59, the spacer plate being formed with holes 58 freely receiving the shanks of bolts 52. The clamp 48 is in the form of an elongated block having a recess 60 in the under side extending from one end of the clamp to the other and being of uniform substantially semi-circular shape throughout its length. The clamp 50 is also in the form of an elongated block disposed parallel with the block 48 and having a recess 62 in the top side directly beneath and parallel with the recess 60, the recess 62 extending from one end to the other of clamp 50 and being of uniform substantially semi-circular shape throughout its length. The diameters of the recesses 60 and 62 are the same.

A tubular bar 64 of uniform inside and outside diameter and of substantially the same outside diameter as the recesses 6 and 62, is adapted to rest upon the clamp 50 in recess 62 and to be clamped between the recesses 6.0 and 62 in the operation of the press. The bar 64 carries a cylindrical pilot pin 66, the pin 66 extending `beyond the end 68 of the bar 64 in concentric relation thereto and carried by a cylindrical plug 70 within the bar. The plug 70 is a cylinder having the same diameter as the inside of bar 64 4so as to support the pilot pin rigidly with respect to the bar and without lateral movement relative thereto, the plug 70 being secured in position by a screw 72 threaded through the wall of the bar and into the plug.

The press also includes a pair of clamps 74 and 76. The clamp 74 is secured to the under side of the` head 42 by a pair of bolts 78, spacers 80 being interposed between the head and clamp 74 and having holes 82 therethrough for freely receiving bolts 78. 'Ihe clamp 76 lies directly beneath clamp74 and has secured-to the under side a pair of guide pins 83 which `depend vertically beneath clamp 76 and are slidably received in vertical openings 84 in the base to guide the vertical movementof clamp 76. relative to the base. The base is also formed witha pair of vertical passages 85, the lower ends of which are counterbored as indicated at 86. The bolts-88 vhave vertical Shanks slidable within the passages 85' with the upper ends ofthe Shanks threadedly securedrto the clamp 76. The enlarged heads 90 of the bolts are freely slidable within the counterbored portions 86 of the passages and are engageable with the shoulders: 91 formed in the passages by the counterbores to limit the upward movement of the clamp 76 relative to the base. Com pression coil springs 94 encircle the guide pins 83 and are compressed between the clamp 76 `and the bottoms of counterbores 95 urging the clamp 76 upwardly to the position shown in Fig. l in whichthe bottoms .of recesses 62 and 98 are at the same level.

The clamp 74 is in the form of an elongated block having a recess 96 in the under side extendingfromone end to the other which is of uniform substantially semicircular shape throughout its length. The clamp 76 is also in the form of an elongated block extending parallel tothe block 74 directly beneath the latter and has a recess 98 extending from one end of the block to the otherof uniform substantially semi-circular shape throughout its length. The diameter rof recess 96 is the same as 4the diameter of recess 98. It will also be noted that these diameters` are the same as those for the recesses 60and 62. Moreover, recesses 62 and 98 are initially in alignment.

ln operation, the bar 64 is placed in recess 62 of clamp 50 in the manner illustrated in Fig. 1, and the tube10 shown in Fig. the outside diameter of the mainV body portion 12 of which is substantially the same, as the diameter of recess 93, is placed in the recess 98`with-.its necked end 14 extending into the end ofibar `64. The inside diameter of barV 64 is substantially the same as the outside diameter of the cylindricalportion 16 of neck 14 to closely receive the latter, and the tube 10 is inserted into the bar until the tapered portion 18 of the neck engages theend 68 of the bar. In this position, the pilot pin 66 extends into the neck 14 and since the pilot pin is of substantially the same diameter as the inside of the cylindrical portion v16 of the neck, the pilot pin provides a full support for the inside of the tubular portion of the neck.

The head is then moved downwardly to the Fig. 2 position. As the head moves downwardly, the clamp 74 engages the upper side of the main body portion of tube and applies a downward force against the main body portion in a direction at right angles'to the tube axis. As the head continues to moveV downwardly, the main body portion of the tube is shifted downwardly relative to the neck portion 14 of the tube. However, because the upper clamp 74 engages the tube 4at or` adjacent to the neck portion, there is very little tendency for the main body portion of the tube to bend downwardly in a clockwise direction about its junction with the neck portion 114. The bar 64 is relatively heavy to hold the neck against any appreciable bending. In other words, the upper clamp 74 has something of a shearing action tending simply to bodily shiftor displace themain body portion 12. During the downward displacement of the main body portion, the supporting clamp 76 yields, and

by reason of the fact that the supporting clamp 76 engages a substantial length of the main body portion 12 from its junction with the neck portion, Vany tendency of the `main body portion to bend downwardly is resisted by` the supporting clamp. The springs 94 are reasonably strong -to substantially oppose `the deformation ofthe 4 tube, thereby assuring an adequate resistance to any tendency toward bending. The guide pins 83 and the bolts 8S are closely confined in vertical passages lto prevent any tilting of the supporting clampV as it moves up and down. Any slight bending of the main body portion of the tube is likely to be transmitted to the bar 64. Although the bar 64 is rather heavy, it is nevertheless possible for the bar to tilt slightly in response to any bending of the main body portion of the tube. However, as pointed out above, the supporting block 76 which is spring supported and accurately guided resists any tendency of the tube to bend. VIn actual practice, kit has been found that very little if any bending exists during this operation of thepress.

At the end of 4the closing movement'of the press, the supporting clamp 76 directly engages the top of the base to prevent further downward movement thereof. At this same moment, fthe upper clamp 48 engages bar V64 to firmly clamp it;V It will be noted that the recesses 60, 62, 96 and 98 are slightly less than semi-circular so that the clamps 48, 50 and 74, 76 do not engage each othery but instead rmly clamp opposite sides of the bar 64 and tube 10. Thus during the final movement of the press to closed position, any bending that might have taken place between the main body portion and necked portion of the tube is straightened out by the nal parallel clamping pressures applied both to the `main body portion of the tube and to the bar 64 supporting the-necrk. As seen, the relative positions of theclamps Yis suchl that the main'body portion of the tube is displaced to a degree such that the side wall of the displaced main body portion is in straight line continuation of the side wall of the necked portion. rlhe tubular bar 64 and thepilot 66 closely conline and support the necked portion ofthe tube to maintain its size-and shape. y f

The drawings and the foregoing specification constitute' a description of the improved method and device for producing oil-center necked lends on spun tubing in such full, clear, concise and exactterms as to enable any person skilled in' the art to practice the invention, rthe scope of which is indicated by the appended claims.

What we claim as our invention is: Y 1. Apparatus for producing a tube having an'oif-center necked end the axis of whichis parallel to the tube axis from a length of tubing having a`main body portion and a necked portion at one end contiguous with said main body portion and concentric therewith, comprising means for holding said necked portion against movement transversely vof the length of tubing including .a bar' havinga tubular portion closely receiving substantially the entire necked portion'and a pilot pin internally supporting said necked portion, clamping means for' said main body portion including a rst member engageable with said main body portion at Yone side thereof adjacent saidlY necked portion upon movement of said iirst member in onedi-A rection at right angles to the axis of said main'bodyportion to move said main body portion transversely to its axis, said clamping means including a' second Vrnenlber engageable with a substantial parti of said main body portion at the opposite side thereof and adjacent to fsaid necked portion in opposition to said rst memben'fsaid second member being movable parallel Vto said 1l1'st'rrnn11-V ber, spring means opposing movement of said second member in said one direction,k thereby to maintain .the

axis of said main body portion parallel vto Vthe'axisof said necked portion during the transverse movement of said main body portion, and an abutment positivelylirn` iting movement vof said second member in jsaid one direction to a limiting position in which the wall of said .d

necked portion extends in subtantially straight line continuation of the wall of the main body portion.

2. Apparatus for producing a tube having anV off-center end the axis of which is parallel to theV tube 'axis from a prising means for holding said end portion against move ment transversely of the length of tubing including a pilot pin internally supporting said end portion, clamping means for said main body portion including a first member engageable with said main body portion at one side thereof adjacent said end portion upon movement of said first member in one direction at right angles to the axis of said main body portion to move said main body porber in said one direction, thereby to maintain the axis 15 of said main body portion parallel to the axis of said end portion during the Vtransverse movement of said main body portion, and an abutment positively limiting movement of second member in said one direction.

References Cited in the file of this patent UNITED STATES PATENTS 1,308,591 James July 1, 1919 10 2,310,498 Turton Feb. 9, 1943 2,477,020 Van Sant July 26, 1949 FOREIGN PATENTS 879,569 France Nov. 30, 1942 879,977 France Dec. 10, 1942 

